I still look forward to any recommendations/comments for the runner-ups (Petris or Optidoctor) or any others brands.

Thanks.

None of the ones sold by RA have a vented cap conversion, either. I doubt that even the AC Delco remans have good sensors in them - they are probably all rebuilt in China. If you plan to go without adding the vented option, then I'd just do the AIP opti.

I guess I'll need to decide if a vented opti is worth the extra money.

Just a little background. I'm retired and have always wanted to have a project car. I really didn't have any particular car in mind, and this corvette pretty much dropped in my lap. PO had issues with it and didn't want to put any more money into it. So it basically turned into a freebie for me. I'm the 3rd owner and don't have any prior maintenance history. Prior to this opti issue, I spent about 1k. (general main, weatherstripping, door panels, head liner, misc stuff, etc).

I like the car, but not really 'in love' with it (yet). My history with the car is about 6 months. Until I get it running again, I don't know how long I'd keep it. Kind of depends if it turns into a money pit.

With that said, going with the lower cost non-vented option might be my choice. With me only driving it on weekends (maybe 2k/yr), I'd be happy if the opti lasts 5+ years. If it does go out, I'll probably tackle the replacement myself.

With that said, going with the lower cost non-vented option might be my choice. With me only driving it on weekends (maybe 2k/yr), I'd be happy if the opti lasts 5+ years. If it does go out, I'll probably tackle the replacement myself.

Thoughts appreciated.

In that case, I'd probably go for the AIP. The replacement is harder than an old-school distributor, but it not nearly as terrible as it's made out to be on the webernets.

send your opti to the opti doctor, he has fast turnaround time. That way it's less money. He inspects, rebuilds (MSD cap & special sealant, etc..), tests it in a "real time environment" with your name on it then sends you a video of the test.

You can contact him (PM here, his name is Brad) for a price. I'm sure if your mechanic doesn't want your optiless sitting around, I'm sure Brad can get it back asap

Unfortunately, per my mechanic, the installed opti is not original. Looks like a knock-off. If it was original, I would consider rebuilding it. Seeing a lot of emphasis on having original Mitsubishi sensor.

Unfortunately, per my mechanic, the installed opti is not original. Looks like a knock-off. If it was original, I would consider rebuilding it. Seeing a lot of emphasis on having original Mitsubishi sensor.

The original sensor is considered the best option, I think. The AIP and Petris units have new sensors that are supposed to be built to a better spec than the crappy Chinese ones on the cheap optis. So probably any of the three choices are good in that respect.

Unfortunately, per my mechanic, the installed opti is not original. Looks like a knock-off. If it was original, I would consider rebuilding it. Seeing a lot of emphasis on having original Mitsubishi sensor.

That is unfortunate. Spend the money on the opti vs 2X the labor to remove and replace a crappy opti (ie: the one you're replacing).

Some info on Optisparks: The Optispark emits a high resolution signal and a low resolution signal to the ECM. On a 92 with OBD1 ECM, if you loose the high res signal, the car will run on low res and may not even throw a code. Some call that, "Limp Mode". It will just be hard to start and won't run great. So if you have not owned the car for long, you might not even know you had an optispark issue until high resolution signals fail. You can test resolution signals on a running car with a two trace oscilloscope. OBD1 cars are hard to diagnose anything as code scanners or the diagnostic dash light procedures display very general areas of information. Anyway, that has been my experience.

Also, if you were running on Limp Mode during your smog test, you probably would have failed it. The cool thing about Texas owners, cars over 25 years old don't get a smog test or smog component inspections. So you can pull your cats and air pumps. Yee Haw..

Things I've done for the engine: New battery; changed oil and filter; replaced plugs and wires; replaced air filter; replaced serpentine belt; added 1 bottle of Techron; ran out most of the old gas and filled with 91 octane.

I just noticed this part of your original post. Make sure to replace the fuel filter. It needs to be replaced every two years or so. It serves to filter the fuel and trap moisture in the fuel system. The 10% Ethanol attracts moisture. It is located behind the front right wheel housing. One good thing about the C4 is it is easy to service the fuel tank and fuel pump as access is from the top through the fuel door.

Warren: Bummed to hear you had issues with the AIP. I searched these threads for any and all info I could find on the best reliable opti. Unfortunately, I did not see yours.

I just purchased the AIP from SacCityCorvette. Hopefully I don't encounter the same issue you did. If I do, if its any consolation for me, I'll have 2 year warranty. According to AIP, the 2 "clamshells" are not sealed with anything. Just a gasket. I don't know if my mechanic would see anything, I'll have him open it and eyeball it before he installs it. Check for anything obvious.

Warren: Bummed to hear you had issues with the AIP. I searched these threads for any and all info I could find on the best reliable opti. Unfortunately, I did not see yours.

I just purchased the AIP from SacCityCorvette. Hopefully I don't encounter the same issue you did. If I do, if its any consolation for me, I'll have 2 year warranty. According to AIP, the 2 "clamshells" are not sealed with anything. Just a gasket. I don't know if my mechanic would see anything, I'll have him open it and eyeball it before he installs it. Check for anything obvious.

Thanks for you input.

Well I did tell AIP about this and also sent them the photos that were in the forum thread. I don't know if they acted on the information. As expected I did not hear back from them.

Update: I purchased the IP opti from SacCityCorvette. Mechanic says he has spark now. Says water pump has been leaking and needs to be replaced. I'll have him add a weep drain tube. Or ask him for the water pump and I'll add ( good write ups on this forum).

Says water pump seal, cam seal, and crank seal all leaking. Mechanic thinks crank seal is pressed in from the inside. Anyone know if the these seals can be replaced without removing the timing cover?

Yeah, opti-seal is easy to replace when doing the job as is water pump seal. Crank seal requires the balancer hub to be pulled which is quite a bit more involved than the the other 2. I did all three without pulling the timing cover off, not sure if that's what's in the "factory service bible" but no leaks so it worked.